node.js basics

Install node.js

It’s easy to install node.js on Windows, just go to node.js official site and download Windows installer, then execute the installer. Congratulations!!! You successfully installed node.js on Windows!!!

A todo list website is a good practice to learn a programing language or a framework. It shows you how to create, read, update and delete records. In this post we are going to use Express as our application framework and MongoDB as our data store.

What is a callback? A callback is a function to be executed after another function is executed. Sounds tongue-twisted? Normally if you want to call function do_b after function do_a the code looks something like

For a long time javascript call and apply have been really confusing me. I neither know when to use it nor what are the differences between these two.

Basically call and apply invoke the function and switch the function context with the first argument. The main difference between these two is with call the rest arguments are passed to the calling function and those arguments have to be listed explicitly. However with apply the amount of arguments don’t have to be predefined. we can pass in an array.

What is `this` in javascript?

We’ve talked about scopes and closures, this points to the current scope object. In client side the highest scope is window and in node.js the highest scope is the global objects.

Javascript is a pretty free language. You can either code in functional programming style or object oriented programming style. With functional programming you pass variables and callbacks around. this is quite useless. However with OOPthis is a must.